Unless otherwise indicated herein, the description in this section is not prior art to the claims in this application and is not admitted to be prior art by inclusion in this section.
The present disclosure relates to a printing system that prints application data, and more particularly to a printing system that can provide stability while performing grayscale printing
A typical image forming apparatus can print characters, line drawings, photos, and other data created by applications in grayscale or black-and-white.
Some applications of PowerPoint (registered trademark) have a unique function to covert color images to be printed to grayscale images or black-and-white images.
FIG. 7 shows an example of color conversion results, obtained when grayscale printing or simple black-and-white printing is performed, for each of different object types.
On the print setting screen for use by applications, the user, for example, can select a desired printing mode from “color”, “grayscale”, and “simple black-and-white” to command printing.
If “grayscale” or “simple black-and-white” is selected, prescribed color conversion is performed for each object, as illustrated in FIG. 7.
When an application having a grayscale conversion function (referred to below as the specific application) is used, however, there is no compatibility between process by the application and process by the printer, so a problem described below may occur.
FIGS. 8A to 8C show a problem related to grayscale printing. FIG. 8A illustrates a case in which an application has not performed grayscale conversion but a printer has performed grayscale conversion. Further, FIG. 8B illustrates a case in which the application has performed grayscale conversion and the printer has also performed grayscale conversion. Yet further, FIG. 8C shows a case in which the application has performed grayscale conversion and the printer has performed color process.
Density in the example illustrated in FIG. 8B is different from density in FIG. 8A, in which some objects have undergone grayscale conversion only on the printer side. This is because grayscale has been performed twice in FIG. 8B. In FIG. 8C, since gray axis fixing, by which the original K value is maintained in conformity with line drawings, has been applied to all image data, a similar problem may occur. This type of problem may be solved by a method in which different color conversion methods are used for different objects or a method in which the density is adjusted for each object. However, these methods are complex and take time.
The present disclosure relates to a printing system in which color conversion appropriate for the color space specified in an application is performed. Further, color conversion is performed so the user can obtain desired output results in both black-and-white printing (grayscale printing), which may be carried out when there is color specification in the application and black-and-white printing (grayscale printing) carried out when there is grayscale specification in the application.